Utility knife



FIG. 1 is a perspective view of a utility knife embodying my new design;

FIG. 2 is a side elevational view of the utility knife;

FIG. 3 is a top plan view of the utility knife;

FIG. 4 is a bottom view thereof;

FIG. 5 is an end view of the utility knife; and,

FIG. 6 is an end view taken from the end opposite that of FIG. 5. 

The ornamental design for a utility knife, as shown. 